Highlights:
- nothing along the northern Gulf Coast will ever be the same
- water that overwhelmed the levees in New Orleans is contaminated with sewage, lead and to a lesser degree pesticides, tests show
- Winds play a role, too, especially along the coast
- We have many questionsLenore Greenstein, Eric Staats (Contact), Sunday, Sep 18, 2005
The Gulf of Mexico’s deep currents follow a path that wiggles and jiggles every year as it loops through waters hundreds of miles offshore.
Oceanographers call it the Loop Current, and its gyrations are getting more attention this year, for the same reason
nothing along the northern Gulf Coast will ever be the same: Hurricane Katrina.
Katrina left behind an environmental catastrophe that scientists and fishermen worry could ride Gulf currents across important fishing grounds off Tampa Bay and into sensitive ecosystems in the Dry Tortugas and Florida Keys.
The
water that overwhelmed the levees in New Orleans is contaminated with sewage, lead and to a lesser degree pesticides, tests show. Crews are draining the city by pumping the water into Lake Pontchartrain, which is connected to coastal waters of the Gulf.
From space, satellites show water working its way south from coastal Louisiana and Mississippi, but nobody yet knows what’s in the water, whether it’s polluted or how it might affect the Gulf.
“We don’t know a lot about this,” University of South Florida oceanographer Frank Muller-Karger said. “We have no experience with an event as major as Katrina.”
Riding the LoopThe Loop Current moves northward into the Gulf between Cuba and the Yucatan Peninsula, loops clockwise in the eastern Gulf and heads south, around the Keys and the tip of Florida and then north into the Atlantic Ocean.Its path varies, as does the distance it pushes north into the Gulf.
On Sept. 7, about a week after Katrina’s disastrous landfall, scientists noticed the Loop Current had moved far enough north to get a hold on waters from coastal Louisiana.
At Roffer’s Ocean Fishing Forecasting Service in Miami, consultant Mitch Roffer is tracking the current using data from two satellites that measure water temperature and ocean color.
Currents move across the Gulf like highs and lows on a TV weather map, except much more slowly, he said. Sometimes, like water moving down a rocky stream, the current spins off eddies, or gyres, he said. Different currents have different temperatures and color, ranging from green to blue.
If part of the Loop Current breaks off, it could have the effect of cutting off the current’s connection with waters along the northern Gulf coast, University of South Florida oceanographer Bob Weisberg said.
A gyre seems to be keeping the Loop Current from reaching even farther north toward the northern Gulf coast, monitors say.
For now, the water from coastal Louisiana is moving south along the eastern edge of the Loop Current and isn’t expected to make a move to Southwest Florida across the shallower waters of the continental shelf.
Along the way, as the water makes its twists and turns with the currents, any contaminants increasingly will be diluted as they mix with the Gulf.
Using computer models, Weisberg estimates that the water could arrive at the Florida Keys by Sept. 20.
The Loop Current isn’t the only force of nature controlling the movement of waters in the Gulf.
Winds play a role, too, especially along the coast, Weisberg said.
The winds haven’t been favorable to push water from the Katrina strike zone onto Florida shores, but that could change in coming weeks, he said.
“We just don’t know,” he said.
That’s what worries fishermen.
‘Fishery failure’
“They’re scared to death,” said Bob Jones, executive director of the Southeastern Fisheries Association, a commercial fishing trade group.
Katrina triggered a declaration by U.S. Commerce Secretary Carlos Gutierrez of a “fishery failure” in the Gulf of Mexico. The Gulf fishing industry is valued at almost $700 million per year.
The declaration clears the way for federal relief funds to restore the fisheries and help fishing communities recover.
The northern Gulf coast is home to 15 fishing ports and 177 seafood processors, according to the National Oceanic and Atmospheric Administration (NOAA).
The storm damaged fishing boats and leveled ports, closed seafood processors and clogged waterways with debris. That could turn out to be just the start, Jones said.
Louisiana environmental officials have reported a 99 percent loss of oyster beds that supply the nation with 40 percent of its oysters.
Murky water from coastal Louisiana already is over grouper fishing grounds off Tampa Bay, said commercial fishermen Bob Spaeth, of Madeira Beach.
It could mean less sunlight reaching the bottom, making it more difficult to sustain marine life that supports the Gulf food chain, he said.
“We’re concerned, obviously, and I think we need to get on top of it,” Spaeth said.
At the Dry Tortugas, a cluster of islands west of Key West, dark water will harm already stressed coral reefs by robbing them of life-sustaining light, said Brian Keller, science coordinator at the Florida Keys National Marine Sanctuary, which takes in the Tortugas.
On the other hand, a little shading could help stressed coral by blocking harmful ultraviolet radiation, he said.
If the murkiness is caused by sediments in the water, they could settle onto the coral, requiring the reefs to use more precious energy to clean themselves, he said.
Scientists and fishermen worry about what else might be in the water that only monitoring will be able to find — and whether enough monitoring is being done.
On the trailA NOAA research ship left Pensacola this past Monday to sample water, sediments and test fish and shrimp along the northern Gulf coast for chemicals and microorganisms that could cause disease.
Part of its mission will be to establish a baseline from which to compare future results, biologists said.
NOAA also chartered a shrimp boat from Bon Secour, Ala., to sample water, sediments and fish and shrimp in Mississippi Sound.
The U.S. Environmental Protection Agency announced Friday that it would dispatch its ocean research vessel Sept. 26 on a three-week survey of Mississippi Sound and into the plume of water from coastal Louisiana.
The Florida Fish and Wildlife Conservation Commission sent a ship along a 30-mile path heading southwest from Panama City to see whether water from coastal Louisiana and Mississippi is moving east along the coast.
Water and sediment samples will be tested for pesticides, metals, industrial chemicals and nutrients that could fuel algae blooms, said Gil McRae, director of the Fish and Wildlife Research Institute, the Conservation Commission’s research arm in St. Petersburg.
McRae said the biggest risk from Katrina is the potential for an overall increase in pollution in the Gulf that could make its way into the food chain and manifest itself years from now.
“It’s an open question how long the impacts of this catastrophe will be seen,” McRae said last week.
Bad water
Details are emerging slowly about what is in the water that has swirled through the streets of New Orleans.
U.S. Environmental Protection Agency Administrator Stephen Johnson acknowledged the enormity of the contamination problem last week during a press conference in Washington, D.C.
“
We have many questions,” he said. “We have many concerns.”
Total coliform and e. coli bacteria, both indicators of human or animal waste, have been found at levels as much as 25 times above the allowed level for contact, according to the EPA.
EPA water samples also show lead, arsenic and a chemical used to make plastics at levels that exceed drinking water standards. In one case, lead was found at levels 56 times the drinking water limit.
Tests also have found mercury, copper, cadmium and various pesticides at lower levels that scientists say still can pose long-term hazards.
The EPA hasn’t released water sampling results since Sept. 10 for bacteria and since Sept. 6 for chemicals.
New Orleans is home to five Superfund cleanup sites, one of them a landfill that still was underwater last week, raising concerns about contaminants leaching from its soils.
Outside of New Orleans, the U.S. Coast Guard has reported five major and four moderate oil spills totaling more than 7 million gallons — about 63 percent of the amount of crude oil the Exxon Valdez spilled into Prince William Sound, Alaska, in 1989.
The EPA reported retrieving more than 20,000 “orphan containers,” including household cleaners, medical waste containers and at least one partially filled drum of acid.
Soils in New Orleans are so laden with petroleum products that laboratories have reported difficulty testing them for anything else, Johnson said last week.
The Coast Guard hasn’t received reports of oil spills in the Gulf of Mexico, but boats have reported an oily sheen in some areas, a spokeswoman said.
Roffer, tracking the Loop Current on computers in Miami, said reports coming from the northern Gulf make him wonder about what might be heading south from the devastated coast.
“It just reiterates to me, to a lot of people, that there are potentially some bad things entering the ecosystem,” Roffer said.
Posted by Dr. Gordon Snyder